In the photographic art, processors are used to render latent images on photosensitive material visible and nonphotosensitive. Typical processors include a series of liquid baths which develop, bleach, fix and rinse (wash) the photosensitive material.
Processor control monitoring is desired for daily start-up and intermittent monitoring of the processor or for image quality problem diagnostic information. Processor control in a typical system, such as the Noritsu QSS 1201, is maintained by the use of control strips. These control strips are specially exposed photosensitive materials usually made by the material manufacturer and provided at a cost to the photofinisher. In a photographic printer, the control strips are used to monitor the processor section isolated from the imaging operation.
In use, the refrigerated control strip is warmed up to ambient temperature, taken to a darkroom, removed from its light-tight package, placed in a dark bag or paper magazine and taken to the processor. A leader card is then attached to the leading edge of the control strip. All processing of photosensitive material is halted. The leader card is inserted into a special light tight slot in the processor where it tows the process control strip through the processor.
The processed control strip is removed from the leader card and brought to a densitometer, such as the X-Rite Model 810, which takes readings of the control strip. The readings from the densitometer are compared to process limits and/or plotted on a hand or off-line computer chart. The processor is considered (1) in control if the densitometer readings fall within acceptable control limits or (2) out of control when the readings fall outside of the control limits. If the processor is out of control, appropriate quality corrective action is initiated. After the corrective action is complete, the above procedure is repeated to determine if the processor is within the control limits.
U.S. Pat. No. 5,083,152 (the '152 reference) discloses a photographic processing device including an exposing section for printing an image on a light-sensitive material in accordance with exposure conditions. A processor section performs developing, fixing, washing and drying operations with respect to the printed light sensitive material. A density measuring unit provided in the vicinity of the light-sensitive material exit side of the processor section photometers the light sensitive material to provide an image density signal. A unit corrects the exposure conditions in accordance with the image density signal.